"Overall shop price inflation is being driven by surging world commodity prices, the effect of the weak pound on import costs and higher VAT -- all beyond retailers' control," said BRC director general Stephen Robertson.

The BRC predicted that there would be further upward price pressure, especially on the cost of non-chilled goods, due to higher grain prices, and also second-round effects from wage rises in commodity-exporting countries.

The lobby group added that food price inflation was running well below broader consumer price inflation, and 39 percent of all grocery items purchased were on promotion.